This invention relates to a method of magnetically recording and reading data while a magnetic head is being subjected to tracking control, a magnetic recording medium used for the method, its production method and a magnetic recording apparatus for recording and reading the magnetic recording medium.
Tracking control has not been necessary in a conventional magnetic recording medium (magnetic disk) which records digital information by a magnetic head because a method has been employed which sufficiently reduces eccentricity of the magnetic recording medium to sufficiently increase a track width and improves accuracy of a mechanism portion of a magnetic recording apparatus to reduce a relative position error between the magnetic recording medium and the magnetic head. In a magnetic recording medium for recording digital data, a magnetic film is sputtered onto a disk substrate such as an aluminum substrate and initial magnetization is effected. Then, the disk is initialized one by one by a servo writer or the magnetic head of the magnetic recording apparatus.
In order to accomplish a higher recording density by reducing further a recording track width of a magnetic recording medium, machining accuracy of the magnetic recording medium and the mechanism portion of the magnetic recording apparatus must be improved but this results in the problems that productivity of the recording medium (magnetic disk) drops, ultra-high precision machining is necessary for the mechanical portion of the magnetic recording apparatus and the magnetic recording apparatus thus becomes too large in scale to achieve reasonable stability and cost.
Since it has not been possible conventionally to replicate in advance fixed information specific to a computer onto a magnetic disk, troublesome procedures of purchasing beforehand a software recorded on a floppy disk and then transferring the information from the floppy disk to a magnetic disk have been necessary to replicate a personal computer software. If the software is large in scale, the number of floppy disks reaches some dozens so that operability of the apparatus drops and a user cannot use it so easily. Moreover, the magnetic disk medium must be initialized one by one by a servo writer or a magnetic recording apparatus after a magnetic film is sputtered onto a disk substrate such as an aluminum substrate and is magnetized initially. Therefore, it has been difficult to replicate large quantities of magnetic disk media having recorded information.
On the other hand, in a magnetic disk (floppy) in which digital data are recorded by a magnetic head while optical tracking control is being made, there has been proposed a system which forms in advance a guide groove in a magnetic medium, guides optically the magnetic head by the aid of this guide groove and records data magnetically ("Nikkei Electronics", Sept. 5, 1988, No. 455).